in-depth survey report: styrene and noise … · naics code: 336612 (boat building) survey date:...

IN-DEPTH SURVEY REPORT STYRENE AND NOISE EXPOSURES DURING FIBER REINFORCED PLASTIC

BOAT MANUFACTURING

at

GRADY-WHITE BOATS INC Greenville NC

REPORT WRITTEN BY Duane Hammond PE Leo M Blade CIH Alberto Garcia MS H Amy Feng MS

Thais C Morata PhD Chucri A Kardous MS PE

REPORT DATE May 2008

REPORT NO 306-12b

US DEPARTMENT OF HEALTH AND HUMAN SERVICES Centers for Disease Control and Prevention

National Institute for Occupational Safety and Health Division of Applied Research and Technology

Engineering and Physical Hazards Branch 4676 Columbia Parkway Mail Stop R-5

Cincinnati Ohio 45226-1998

SITE SURVEYED Grady-White Greenville North Carolina

NAICS CODE 336612 (Boat Building)

SURVEY DATE September 26-28 2007

SURVEY CONDUCTED BY Leo M Blade CIH NIOSH Cincinnati OH

Alberto Garcia MS NIOSH Cincinnati OH

Duane Hammond PE NIOSH Cincinnati OH

EMPLOYER REPRESENTATIVES Jim Hardin CONTACTED Compliance Manager Grady-White

ii

DISCLAIMER

Mention of company names or products does not constitute endorsement by the Centers for Disease Control and Prevention

The findings and conclusions in this report are those of the authors and do not necessarily represent the views of the National Institute for Occupational Safety and Health

iii

ACKNOWLEDGEMENT

The authors of this report thank the National Marine Manufacturers Association and Grady White Boats Inc for their efforts on behalf of this study and their assistance in arranging the site visits

iv

ABSTRACT

A three-day in-depth field survey was performed to assess the occupational exposures of styrene vapors and to evaluate the effectiveness of the engineering controls currently installed for reducing styrene exposures during a fiberglass reinforced plastic (FRP) boat manufacturing processes The primary objective of this study was to quantify exposures at a boat manufacturing facility that uses ventilation low styrene resins and non-atomizing spraying techniques to reduce emissions and worker exposures during open-mold manufacturing of fiberglass boats A secondary objective was to assess the noise levels occurring during jobs which involve the use of styrene-based products The effectiveness of the styrene controls examined in this study was evaluated by measuring styrene concentrations in personal breathing-zone and general-area samples during typical work shifts The general-area air sample results were below 14 parts per million (ppm) for all of the areas sampled The lowest personal breathing-zone samples were measured from workers in the closed-mold job category which resulted in a geometric mean styrene concentration of 85 ppm The personal breathing zone samples of workers in the open-molding processes ranged from a geometric mean styrene concentration of 20 ppm for the gelcoaters to 92 ppm for the stringer glass-in workers One of the twenty-one personal breathing zone samples from hull laminators was higher than 100 ppm Six of the twelve personal breathing zone samples from stringer glass-in workers were higher than 100 ppm Three of the personal breathing zone samples higher than 100 ppm were measured from the same worker each day for three consecutive days A change in work practices could likely reduce these high exposures Additional recommendations for reducing exposures include increasing ventilation for stringer glass-in workers and hull laminators The continued use of respirators with organic vapor cartridges is also recommended Results from workers who are considered to be exposed to both styrene and noise indicated that most of the styrene exposures for this group are equal or below 43 ppm If any of the workers in this group develop a hearing loss that cannot be explained by their noise exposure he or she should be referred to his or her physician for further examination

1

INTRODUCTION

The National Institute for Occupational Safety and Health (NIOSH) is part of the Centers for Disease Control and Prevention (CDC) in the US Department of Health and Human Services (DHHS) NIOSH was established in 1970 by the Occupational Safety and Health (OSH) Act at the same time that the Occupational Safety and Health Administration (OSHA) was created in the US Department of Labor (DOL) The OSH Act mandated NIOSH to conduct research and education programs separate from the standard-setting and enforcement functions conducted by OSHA An important area of NIOSH research involves measures for controlling occupational exposures to potential chemical and physical hazards

On September 26-28 2007 researchers from the Engineering and Physical Hazards Branch (EPHB) of the Division of Applied Research and Technology (DART) conducted an in-depth survey at Grady-White Boats Inc in Greenville North Carolina The primary purpose of the evaluation was to measure styrene exposures at a boat manufacturing facility that uses modern ventilation low styrene resins and non-atomizing spraying techniques to reduce emissions and worker exposures during open-mold manufacturing of fiberglass boats A secondary objective was to evaluate noise exposures occurring during these operations

The effectiveness of preventing styrene exposures was evaluated in terms of personal breathing-zone styrene exposures Personal breathing zone (PBZ) air sampling was used to measure worker exposures to styrene In addition styrene concentrations in general-area air were measured at various fixed locations throughout the facility For this report effective engineering controls are those that maintain styrene exposures below applicable occupational exposure criteriamdashthe NIOSH Recommended Exposure Limit (REL) the American Conference of Governmental Industrial Hygienists (ACGIHreg) Threshold Limit Value (TLVreg) or the OSHA Permissible Exposure Limit (PEL)

This report will focus on the documentation of styrene exposures measured during the closed- and open-molding manufacturing processes In addition engineering control and work-practice recommendations will be offered where styrene exposures exceed the NIOSH or OSHA exposure criteria

Styrene Usage and the Hazards of Exposure to Styrene and Noise

Styrene Usage The major chemical component of concern in terms of occupational exposures in the fiberglass reinforced plastic (FRP) process is styrene Styrene is a fugitive emission which evaporates from resins gel coats solvents and surface coatings used in the manufacturing process The thermo-set polyester resin used at this plant is Maximum Achievable Control Technology (MACT) compliant and contains 33 to 34 percent styrene by weight Styrene is an essential reactive diluent for polyesters because it reduces the viscosity of the polyester mixture making it thinner and more capable of coating fiber

2

reinforcements allowing the reactive sites on the molecules to interact As an active diluent styrene will react in the free-radical cross-linking reaction Cross-linking is the attachment of two chains of polymer molecules by bridges composed of molecular in this case styrene and primary chemical bonds It produces a solid resin material that is impervious to most solvents petroleum and other chemicals found in the marine environment Since styrene is consumed as part of this reaction there is no need for removal of the diluents after the part is formed However vapors from the application and curing process may pose an inhalation exposure hazard for workers near the process

Hazards of Styrene and Exposure Limits Humans exposed to styrene for short periods of time through inhalation may exhibit irritation of the eyes and mucous membranes and gastrointestinal effects1 Styrene inhalation over longer periods of time may cause central nervous system effects including headache fatigue weakness and depression Exposure may also damage peripheral nerves and cause changes to the kidneys and blood Numerous studies have shown that styrene exposures were linked to central and peripheral neurologic234 optic56 and irritant7 effects when occupational exposures to styrene vapors in air were greater than 50 parts per million (ppm) There is also evidence concerning the influence of occupational styrene exposure on sensory nerve conduction indicating that (1) 5 to 10 reductions in sensory nerve conduction velocity can occur after exposure at 100 ppm or more (2) reduced peripheral nerve conduction velocity and sensory amplitude can occur after styrene exposure at 50 to 100 ppm (3) slowed reaction time appears to begin after exposures as low as 50 ppm and (4) statistically significant loss of color discrimination (dyschromatopsia) may occur8 Some other health effects of low-level styrene exposure include ototoxicity in workers and experimental animals Styrene exposure can cause permanent and progressive damage to the auditory system in rats even after exposure has ceased910 Styrene has been shown to be a potent ototoxicant by itself and can have a synergistic effect when presented together with noise or ethanol11121314

The primary sources of environmental evaluation standards and guidelines for the workplace are (1) the OSHA PEL15 (2) The NIOSH REL16 and (3) the ACGIHreg

TLVreg19 Employers are mandated by law to follow the OSHA limits however employers are encouraged to follow the most protective criteria The NIOSH REL for styrene is 50 ppm for a 10-hour time-weighted average (TWA) (meaning the limit applies to the average exposure during a work day of up to 10 hours and a work week of up to 40 hours) with a 15-minute short-term exposure limit (STEL) of 100 ppm limiting average exposures over any 15-minute period during the work day 17 These recommendations are based upon reported central nervous system effects eye irritation and respiratory irritation The OSHA PEL for styrene is 100 ppm for an 8-hour TWA exposure with a ceiling limit of 200 ppm18 The ceiling limit restricts exposures for any portion of the work day The ACGIHreg revised its TLVreg in 1997 and recommends styrene be controlled to 20 ppm for an 8-hour TWA exposure with a 40 ppm 15-minute STEL 19

Standards and guidelines for occupational exposure to styrene are also found internationally The Swedish Work Environment Authority has an occupational exposure level limit value (LLV) for styrene of 20 ppm and a short term value (STV) of 50 ppm20

3

The German Federal Institute for Occupational Safety and Health has an occupational exposure limit value of 20 ppm for styrene21

In February 1996 Styrene Information and Research Center (SIRC) and three other styrene industry trade associations (American Composites Manufacturers Association National Marine Manufactures Association and the International Cast Polymer Association) entered into a precedent-setting arrangement with OSHA to voluntarily adhere to the 50-ppm level set by the 1989 update of the OSHA PEL (which was later vacated by the courts) The SIRC encouraged its members to continue to comply with the 50-ppm standard as an appropriate exposure level for styrene regardless of its regulatory status22

Maximum Achievable Control Technology The EPA has identified the FRP boat manufacturing industry as a major source of Hazardous Air Pollutants (HAPs)mdashmainly styrene The final MACT regulation was issued to reduce HAPs for new and existing boat manufacturing facilities The MACT standard affects any boat manufacturing stationary facility that emits or can potentially emit 10 tons per year of a single HAP or 25 tons per year of combined HAP The MACT covers (1) open molding resin and gel coat operations (2) resin and gel-coat mixing operations (3) resin and gel-coat application equipment cleaning operations (4) carpet and fabric adhesive operations The MACT standard requires boat manufacturers using open molding to adopt stringent air pollution control technologies in order to reduce environmental releases of styrene vapor in the air Closed molding is one method for demonstrating compliance with the Boat Manufacturing MACT Under the rule boat manufacturers wishing to continue using open-molding operations must use one of the following options (1) purchase materials that meet the organic HAP content requirement (2) meet the HAP content requirements for resin and gel-coat operations on a weighted average basis (3) use emissions averaging among different resin and gel-coat operations or (4) use an add-on control device Closed molding is exempt from the MACT standard23

Noise Hazards and Exposure Limits Hazards from exposure to noise include hearing loss from long-term over-exposures and from transient periods of high impulse noise The OSHA standard for occupational noise exposure 29 CFR 191095 specifies a maximum PEL of 90 decibels A-weighted (dBA) averaged over an 8-hour time period The OSHA standard states that exposure to impulse noise (eg firearms) should not exceed 140 dB sound pressure level (SPL)24 The regulation uses a 5 dB exchange rate trading relationship This means for example that if a person is exposed to average noise levels of 95 dBA the amount of time allowed at this exposure level must be cut in half (to 4 hours) in order to be within OSHArsquos PEL Conversely a person exposed to 85 dBA is allowed twice as much time at this level (16 hours) and is within his daily PEL The OSHA regulation has an additional action level (AL) of 85 dBA which stipulates that an employer shall administer a continuing effective hearing conservation program when the 8-hour time-weighted average or TWA exceeds the AL The program must include monitoring employee notification observation an audiometric testing program hearing protectors training programs and record keeping

4

requirements The standard also states that when workers are exposed to noise levels in excess of OSHArsquos PEL of 90 dBA feasible engineering or administrative controls shall be implemented to reduce workersrsquo exposure levels

The NIOSH REL for noise (8-hour TWA) is 85 dBA using 3-dB exchange rate trading relationship25 NIOSH also recommends that no impulse exposure be allowed above 140 dB peak SPL The ACGIHreg TLVreg for noise is 85 dBA (8-hour TWA) with 3-dB exchange rate and 140 dB SPL as a maximum impulse exposure limit18

Facility Description Grady-Whitersquos facility located in Greenville North Carolina has 350000 ft2 of floor area and employs 360 to 470 people depending on demand This is the only facility that manufactures Grady-White brand boats The boat size range is from 18 to 36 feet (ft) in length The facility operates one shift per day beginning at 700 AM

The manufacturing portion of the building is split into three production bays Bay 1 is located on the west side and houses hull lamination Bay 2 located in the center is the site of lamination of decks and liners Bay 3 located on the south side of the facility includes the closed-mold production of small parts in its southern section and the open-molding production in its northern section There are approximately 42 employees working in two of the three bays A plan view of the controlled-flow ventilation is shown in Figure 1 and a typical cross-sectional side view (of bay 2) is shown in Figure 2 Outside air is supplied from above the lamination process and exhausted perpendicular to the supply region as seen in Figure 1 and 2 below The arrows shown in Figure 1 and 2 depict the air movement across the hulls decks and liners (orange figures) The ventilation system was tested by the engineering firm that designed and installed the ventilation system The test consisted of ribbon pole and smoke testing for detection of airflow and any potential dead spots

C

Bay 1

Airflow

Bay 3Bay 2

A

B

Storage

Stringer Installation

Molds

Figure 1 Plan View of Controlled-flow Ventilation installed by Frees Inc (A) Vertical takeoffs (B) Filter surfaces (C) Vertical supply duct

5

Supply air

Exhaust Plenum

Work Area

Direction of Airflow

Exhaust

Filter Surface Floor

Hull Deck Liner Representation

Figure 2 Side View of Controlled-flow Ventilation installed by Frees Inc

Process Description The FRP boat manufacturing process mainly used at Grady-White is an open-molding process Cold-press pneumatic molding (a form of closed molding) is used to fabricate small hatch covers All of the parts that make up a Grady-White boat are designed using Computer-Aided Design (CAD) and Computer-Aided Manufacturing (CAM) systems Frame designs were sent directly from the CAD system to the computer-controlled router for output All boat designs are built in wood or urethane foam prior to production The fiberglass molds used for production are made from these plugs

Open Molding Fiberglass boats are built from glass-fiber reinforcements laid in a mold and saturated with a polyester resin The plastic resin hardens to form a rigid plastic part reinforced with the fiberglass The process starts with gelcoating The mold is sprayed with a layer of gel coat which is a pigmented polyester resin that hardens and becomes the smooth outside surface of the part The lamination process begins with the placement of the preshycut fiberglass mats and is followed by the saturation of resin into the fiberglass mats All fiberglass mats are hand-laid to provide a uniform laminate structure The dry mat used is of high porosity to allow resin penetration within the fiberglass structure of the mat during resin saturation (rolling process) Hull molds were rotated sideways during lamination which allows the air to pass through the hull area and then be pulled from behind into the exhaust system The laminator worked standing approximately twelve inches from the mold Workers wore half-mask 3M respirators with organic vapor cartridges when stringers (wood reinforcements) were installed and covered with a layer

6

of fiberglass The orientation of the boat when laminating has to be rotated on its side due to the nature of the process and the detailed crevices in the hulls of the boat

A chopper gun (cuts fiberglass thread into small one inch pieces and sprays chopped glass and resin into the mold) is used for small parts and liners only The hand-laid fiberglass mats and chopped fiberglass pieces are saturated with resin by a gunner using a MACTndashcompliant low-flow non-atomizing gun The resin in each part is metered measured and entered into the computer system so every part contains an optimal glass-to-resin ratio The saturated resin is then hand-rolled and compressed by the rollers The laminators and gunners do not wear respirators Once the fiberglass mats and resin are applied and the desired thickness has been achieved on some models a stringer system built of treated plywood is cut by a computerized router system and then glassed into the hull while it is still in the mold The preassembly of the stringer systems occurs in the southwest end of the building adjacent to the closed molding process All employees in lamination and grinding are enrolled in the hearing conservation program and are required to wear hearing protection

Closed molding The cold-press pneumatic molding process is used only for small parts The process consists of mixing together a resin a catalyst (methyl ethyl ketone peroxide or MEKP) and a filler and pouring the mixture into a mold that has already been loaded with glass reinforcement The duty of the operator is to meter the resin mixture and pour the resin mixture into the mold It is then placed into the pneumatic clamp machine and pressed It takes about five minutes for the process to cure Two molds are poured per process Styrene is emitted from the process as the molds are loaded

Resin Storage Area There are two 6000-gallon resin tanks stored outside of the facility One full tank of resin is used every 4 or 5 days All of the tanks are jacketed to assure a storage temperature of 75-80 degrees Fahrenheit The temperature is controlled by water through a shell-and-tube heat exchanger

METHODS

Air Sampling for Styrene Personal breathing-zone and general-area air samples for styrene were collected and analyzed in accordance with NIOSH Method 1501 (Hydrocarbons Aromatic) (NMAM NIOSH Manual of Analytical Methods)26 Samples were collected on SKC sorbent tubes (Model number 226-01 Anasorb CSC Coconut Charcoal Lot 2000) The tubes were 7 centimeters (cm) long with a 6 millimeter (mm) outer diameter and a 4-mm inner diameter The ends were flame-sealed and contained two sections of activated coconut shell charcoal 100 milligrams (mg) in front and 50 mg in back separated by a 2-mm urethane foam plug A glass wool plug precedes the front section and a 3-mm urethane foam plug follows the back section After breaking the sealed ends each tube was

7

connected to a Gilian low flow pump or an SKC Pocket Pump set at a nominal flow rate of 03 liters per minute (Lmin) The pumpsrsquo actual flow rates were calibrated before and after sampling For personal breathing-zone air samples the air inlet of the sampling apparatus was secured in each workerrsquos breathing zone with a lapel clip and the battery-powered pump clipped to the workerrsquos belt In addition field blank samples were created each day to ensure that the sample media was not contaminated and to account for any variance in sample preparation

The analyses of the charcoal tube samples for styrene were performed by Bureau Veritas North America Inc in Novi Michigan The samples were analyzed by removing the individual sections of the charcoal tube and placing them into separate vials The glass wool and the foam plugs that divide the sections of charcoal were discarded The individual sections were then chemically desorbed by using 1 milliliter (mL) of carbon disulfide The samples were placed on a mechanical shaker for a minimum of 30 minutes before analyzed by gas chromatography with flame ionization detection (GCFID) in accordance with NIOSH Method 1501 The limit of detection and limit of quantification for styrene for this sample set was 033 and 293 ppm respectively

General-area air samples were collected to better understand the effectiveness of the installed engineering controls using the same type of sampling apparatus as used for the personal air sampling These samples were placed in stationary locations to determine how well the ventilation system was performing throughout the plant and to assess the spread of the styrene vapor throughout the facility Area samples were placed near the liner and deck lamination area the closed-mold area small part lamination and hull lamination areas

Once the sample results were received from the analytical laboratory the styrene breathing zone concentrations and general-area concentrations were calculated using Equation 1 The concentration in milligrams per meter cubed was converted to parts per million

mC (1)

V 426

Where C = styrene concentration ppm m = mass of styrene per sample μg V = volume of air sample L Note 426 is the constant used for styrene to convert from microgL (mgm3) to ppm obtained from NMAM (NIOSH Manual of Analytical Methods) 1501(Hydrocarbons Aromatic)

Noise Measurements In addition to measurements of plant ventilation and styrene exposure noise exposures were also measured Eight-hour personal and area noise level measurements were collected using ten Quest Noise Pro dosimeters A total of eighteen personal full shift measurements were collected during the survey from twelve workers who were also exposed to styrene Each dosimeter was capable of collecting noise data in one second

8

increments The dosimeters were set to simultaneously measure the OSHA PEL and the NIOSH REL The dosimeters conformed to the American National Standards Institute (ANSI S125-1997)27 specifications Dosimeters were set to ldquoSLOWrdquo response and A-weighting frequency filter The equipment was calibrated by the manufacturer before the study Field calibrations checks were conducted before measurements using a Quest calibrator Data from the dosimeters were downloaded to a personal computer and analyzed using the Quest Suite Professional II software

STATISTICAL ANALYSIS AND RESULTS

Air Sampling for Styrene Appendix 1 contains the job title date sample ID result in microgsample and concentration in ppm for the samples collected during the three day survey The sample results were checked for normality using the Shapiro-Wilk test Subsequently all data were natural log-transformed for statistical analysis Personal-sample and area-sample data were analyzed separately

Data for personal samples were analyzed using the mixed-model procedure with repeated measure options No statistically significant day-to-day difference was found among the measured personal exposures (p=021) However statistically significant differences in exposure levels were found among job categories (p lt0001) Scheffes and Bonferronis adjustment were then used with the mixed model procedure for multiple comparison among job categories Both Scheffersquos and Bonferronirsquos adjustment methods concluded with the following same results Workers in the stringer glass-in (geometric mean exposure (gmean) = 92 ppm) job category had significantly higher exposures than the exposures of workers in all other evaluated jobs Hull laminators (gmean = 43 ppm) had significantly higher exposures than the exposures of linerdeck laminators (gmean = 24 ppm) gelcoators (gmean = 20 ppm) and closed-molding operators (gmean = 85 ppm) Statistically significant differences were not found between hull laminators and small parts laminators or between small parts laminators linerdeck laminators and gelcoaters Closed mold operators (gmean 85 ppm) had significantly lower exposures than the exposures of stringer glass-in (gmean = 92 ppm) hull laminators (gmean = 43 ppm) small parts laminators (gmean = 37 ppm) and linerdeck laminators (gmean = 24 ppm)

The nonparametric method of the Kruskal-Wallis Test was used to test differences among measured area sample concentrations of styrene No statistically significant differences were found among areas (p gt005) The nonparametric method of the Kruskal-Wallis Test was also used to test for differences among days for each of the four evaluated areas (liners decks closed molding hulls and small parts) No statistically significant differences were found among days (pgt005) for each of the four areas Geometric mean geometric standard deviation geometric mean 95 confidence limits and sample size for comparison of personal and area air styrene samples are included in Table I

9

Table I Geometric Mean 95 confidence intervals sample size and standard deviation for personal and area air styrene concentrations in ppm

Geometric Geometric Geometric

Geometric Mean Lower MeanSample Mean

Job Category Mean n 95 Upper 95Type standard

(ppm) Confidence Confidence Deviation

Interval Interval Area Area (liners decks) 11 6 72 17 15 Area Area (closed molding) 87 2 60 13 10 Area Area (hulls) 13 6 84 21 16 Area Area (small parts) 97 5 74 13 13

Personal Closed mold operator 85 6 68 11 12 Personal Gelcoater 20 8 12 35 19 Personal Hull laminator 43 21 34 55 17 Personal LinerDeck laminator 25 23 17 36 24 Personal Small Parts laminator 37 8 34 40 11 Personal Stringer Glass-In 92 12 73 120 15

Noise Dosimetry Summaries of the personal exposure dosimetry measurements are shown in Table II The results show the time-weighted average in A-weighted decibels (dBA) and dose (in percentage) of the measurements based on the NIOSH and OSHA criteria for different job titles and tasks

Table II Summary results of personal styrene measurements and range of the results of the noise dosimetry for different job titles and job tasks (number of samples indicate cases where both exposures were assessed for the same worker)

Job title Mean styrene OSHA NIOSH n or task concentration TWA OSHA TWA NIOSH

(ppm) dBA Dose dBA Dose Hull 43 867-897 635-965 914-944 450-900 4 laminator Closed 85 827-879 37-75 892-922 300-534 3 molding operator Linerdeck 25 892-92 90-119 944-954 874-1121 4 laminator Small parts 37 892-924 90-141 94-974 797-1741 3 laminator Stringer 92 833-858 40-56 884-909 250-400 4 Glass-In

10

DISCUSSION

The results from the personal and area air styrene measurements from this study indicate that mean styrene concentrations were reasonably well controlled and below the OSHA PEL of 100 ppm for the majority of the processes in the plant However six of the personal breathing-zone samples measured from stringer glass-in workers and one measurement from hull laminators were higher than 100 ppm Three of the seven personal samples higher than 100 ppm were measured from a single worker every day for three consecutive days Two of the personal samples higher than 100 ppm were measured from another worker on two consecutive days Actual worker exposures were likely much lower since workers in the stringer glass-in area and hull lamination wore half-mask respirators with organic vapor cartridges

Noise measurements results showed large differences when calculations for time-weighted averages and dose were done using either the OSHA exchange-rate of 5 dB or NIOSHrsquos rate of 3 dB NIOSH has found that scientific evidence supports the use of a 3shydB exchange rate for the calculation of a TWA for noise28 The premise behind the 3-dB exchange rate is that equal amounts of sound energy will produce equal amounts of hearing impairment regardless of how the sound energy is distributed in time

These workers whose noise exposure measurements were obtained are already in the companyrsquos hearing conservation program Their noise exposures are quite different by job title and task indicating different needs regarding hearing loss prevention Workers who are exposed to lower noise levels do not need as much attenuation In their case the concern should be to avoid over-attenuation because it might discouraged the workers from wearing the hearing protection Details on how to select appropriate hearing protection and on other phases of an effective hearing conservation program can be found in the NIOSH criteria document28 or part (a) of the OSHA noise exposure standard29

One of the main goals of the study is to evaluate occupational exposures occurring from the closed molding process and to compare the results with results from exposures occurring near open molding processes However it was not possible to independently compare the two processes since closed molding and open molding shared the same room and ventilation space The geometric mean of the personal sample concentrations of the closed molding workers (gmean = 85 ppm) was lower than the geometric mean concentrations of any of the area sample collected at other location in the plant and lower than the area sample concentrations for the closed molding area (gmean = 87 ppm) Therefore the personal exposures of the closed molding workers were more representative of the styrene concentrations in the well mixed plant air and apparently not appreciably affected by styrene emissions from the closed molding process It was not possible to evaluate exposures from the closed molding process independently from other processes taking place in the plant It is expected that exposures resulting from the closed molding process would be lower than the results measured during this evaluation if the closed molding area did not share ventilation space with open molding processes

11

CONCLUSIONS AND RECOMMENDATIONS

At the time of this evaluation the majority of the measured personal breathing-zone air styrene concentrations were below the OSHA PEL of 100 ppm and NIOSH REL of 50 ppm However seven of the personal breathing-zone samples were higher than 100 ppm Six of the seven personal breathing-zone measurements higher than 100 ppm were measured during the stringer glass-in process Workers in the stringer glass-in (gmean = 92 ppm) job category had significantly higher exposures than the exposures of workers in all other evaluated job categories The higher concentrations were likely due to the orientation of the boats and the entrapped air in the hull It is recommended that additional ventilation be supplied to the hull cavity to reduce worker exposures during the stringer glass-in process Actual exposures were likely much lower since workers in the stringer glass-in area wore half-mask respirators with organic vapor cartridges However additional ventilation should be supplied to the stringer glass-in area to reduce concenshytrations below 100 ppm The following recommendations are provided to further reduce styrene concentrations in an effort to help provide a safer and healthier environment

Although the majority of the personal breathing-zone samples were below regulatory limits measurements indicated that personal breathing-zone concentrations were higher than recommended exposure limits such as the 20 ppm TLVreg recommended by ACGIHreg and European standards such as the 20 ppm occupational exposure level limit values set by the Swedish Work Environment Authority and the 20 ppm exposure limit set by the German Federal Institute for Occupational Safety and Health Efforts should be made to keep styrene concentrations below recognized exposure criteria that are most protective whenever possible

When possible workers performing rolling operations should be on the supply side of the ventilation system relative to the gun operator This will help prevent air currents from directing styrene emissions from the gun directly into the breathing zone of the workers performing rolling tasks

The continued use of the organic-vapor charcoal-filter respirators is highly recommended especially for those workers involved in the stringer glass-in process Personal breathing-zone samples for styrene vapor were reasonably well controlled in the remainder of the plant outside of the hull lamination area The ventilation systems effectively controlled worker exposures to styrene vapor in the majority of the plant

Regarding the group of workers who are considered to be exposed to both styrene and noise (at levels that triggered their inclusion in the companyrsquos hearing conservation program) results indicated that most of the styrene exposures for this group are equal or below 43 ppm If any of the workers in this group develop a hearing loss that cannot be explained by their noise exposure he or she should be referred to his or her physician for further examination

12

REFERENCES

1 Environmental Protection Agency (EPA) National Emission Standards for Hazardous Air Pollutants for Boat Manufacturing Proposed Rule Part II 40 CRF Part 63 July 14 2000

2 Mutti A Mazzucchi A Rustichelli P Frigeri G Arfini G Franchini I Exposure-effect and exposure-response relationships between occupational exposure to styrene and neuropsychological functions Am J Ind Med 5275-286 (1984)

3 Fung F Clark RF Styrene-induced peripheral neuropathy Journal of Toxicology - Clinical Toxicology 37(1)91-7 (1999)

4 Tsai SY Chen JD Neurobehavioral effects of occupational exposure to low-level styrene Neurotoxicology amp Teratology 18(4)463-9 (1996)

5 Gong Y Y R Kishi et al Relation between colour vision loss and occupational styrene exposure level Occupational amp Environmental Medicine 59(12) 824-9 (2002)

6 Triebig G T Stark et al Intervention study on acquired color vision deficiencies in styrene-exposed workers Journal of Occupational amp Environmental Medicine 43(5) 494-500 (2001)

7 Minamoto K Nagano M Inaoka T Futatsuka M Occupational dermatoses among fibreglass-reinforced plastics factory workers Contact Dermatitis 46(6)339-47 (2002)

8 American Conference of Governmental Industrial Hygienists (ACGIH) Documentation of Threshold Limit Values and Biological Exposure Indices TLVreg for Styrene American Conference of Governmental Industrial Hygienists Cincinnati OH (2001)9 Campo P Lataye R Loquet G Bonnet P Styrene-induced hearing loss a membrane insult Hearing Research 154(1-2)170-80 (2001)

10 Lataye R Campo P Pouyatos B Cossec B Blachere V Morel G Solvent ototoxicity in the rat and guinea pig Neurotoxicology amp Teratology 25(1)39-50 (2003)

11 Morata T C A C Johnson et al ldquoAudiometric findings in workers exposed to low levels of styrene and noise Journal of Occupational amp Environmental Medicine 44(9) 806-14 (2002)

12 Sliwinska-Kowalska M Zamyslowska-Smytke E Szymczak W Kotylo P Fiszer M Wesolowski W Pawlaczyk-Luszczynska M Ototoxic effects of occupational exposure to styrene and co-exposure to styrene and noise Journal of Occupational and Environmental Medicine 45 (1) 15-24 (2003)

13

13 Makitie AA Pirvola U Pyykko I Sakakibara H Riihimaki V Ylikoski J The ototoxic interaction of styrene and noise Hearing Research 179(1-2)9-20 (2003)

14 Lataye R Campo P Loquet G Combined effects of noise and styrene exposure on hearing function in the rat Hearing Research 139(1-2)86-96 (2000)

15 Occupational Safety and Health Administration Code of Federal Regulations 29 CFR 1910 ldquoOccupational Safety and Health Standardsrdquo US Government Printing Office Office of the Federal Register Washington DC (2002)

16 National Institute for Occupational Safety and Health ldquoRecommendations for occupational safety and health compendium of policy documents and statementsrdquo US Department of Health and Human Services Public Health Service Centers for Disease Control and Prevention National Institute for Occupational Safety and Health DHHS (NIOSH) Publication No 92B100 (1992)

17 National Institute for Occupational Safety and Health (NIOSH) NOISH Pocket Guide to Chemical Hazards and Other Databases ndash REL for Styrene DHHS (NIOSH) Pub No 2004-103 (2004)

18 Occupational Safety and Health Administration (OSHA) OSHA National News Release US Department of Labor Office of Public Affairs News Release USDL 96-77 March 1 1996

19 American Conference of Governmental Industrial Hygienists (ACGIH) TLVsreg

and BEIsreg Threshold Limit Values for Chemical Substances and Physical Agents amp Biological Exposure Indices American Conference of Governmental Industrial Hygienists Cincinnati OH (2004)

20 Swedish Work Environment Authority Provisions of the Swedish National Board of Occupational Safety and Health on Occupational Exposure Limit Values and Measures against Air Contaminants (SE-171 84) Solna Sweden SWEA 2000

21 Bundesanstalt fuumlr Arbeitsschutz und Arbeitsmedizin Technische Regeln fuumlr Gefahrstoffe Arbeitsplatzgrenzwerte 2006 httpwwwbauadenn_16806deThemenshyvon-A-ZGefahrstoffeTRGSpdfTRGS-900pdf

22 Office of Public Affairs (Washington DC) [1996] OSHA announces that styrene industry has adopted voluntary compliance program to improve worker protection News Release 01 March 1996 Washington DC httpwwwacmanetorggaosha_styrene_agreement_docs_1996pdf

14

23 US Environmental Protection Agency (EPA) [2001] Fact Sheet Final regulation to reduce toxic air pollutant emissions from the boat manufacturing industry August 14 2001

24 Occupational Safety and Health Administration Code of Federal Regulations 29 CFR 191095 ldquoOccupational Exposure to Noiserdquo US Government Printing Office Office of the Federal Register Washington DC (1992)

25 National Institute for Occupational Safety and Health Criteria for a recommended standard mdash Occupational noise exposure (revised criteria 1998) Cincinnati OH US Department of Health and Human Services Public Health Service Centers for Disease Control and Prevention National Institute for Occupational Safety and Health DHHS (NIOSH) Publication No 98-126 (1998)

26 National Institute for Occupational Safety and Health (NIOSH) [1994] NIOSH manual of analytical methods 4th edition Cincinnati OH US DHHS (NIOSH) Publication No 94-113

27 American National Standards Institute Specification for Personal Noise Dosimeters ANSI S125-1991 (R1997) New York New York

28 National Institute for Occupational Safety and Health (NIOSH Criteria for a Recommended Standard Occupational Exposure to Noise (Rev Criteria) Cincinnati OH 1998 Publication No 98-126


APPENDIX I Sample Mass Concentration

Job Title or Area Sample Date (2007) SampleID (ugsample) (ppm) Area (hulls) 26-Sep 28 520 10 Area (hulls) 26-Sep 29 1300 26

Area (Liners Decks) 26-Sep 32 760 16 Area (Liners Decks) 26-Sep 33 540 10 Area (small parts) 26-Sep 30 520 10 Area (small parts) 26-Sep 31 430 85

BLANK 26-Sep 6 0 NA BLANK 26-Sep 7 0 NA BLANK 26-Sep 8 0 NA

Closed Molding Operator 26-Sep 18 370 71 Closed Molding Operator 26-Sep 21 410 79

Hull Laminator 26-Sep 3 6300 140

15

Hull Laminator 26-Sep 9 5000 92 Hull Laminator 26-Sep 11 2700 52 Hull Laminator 26-Sep 13 2000 37 Hull Laminator 26-Sep 15 2400 43 Hull Laminator 26-Sep 16 870 16 Hull Laminator 26-Sep 23 3100 59

LinerDeck Laminator 26-Sep 10 630 13 LinerDeck Laminator 26-Sep 12 1500 32 LinerDeck Laminator 26-Sep 14 1200 25 LinerDeck Laminator 26-Sep 19 1300 26 LinerDeck Laminator 26-Sep 20 1800 36 LinerDeck Laminator 26-Sep 24 2300 46 LinerDeck Laminator 26-Sep 26 3500 69 Small Parts Laminator 26-Sep 1 1500 43 Small Parts Laminator 26-Sep 22 1900 34 Small Parts Laminator 26-Sep 25 1900 36

Stringer Glass-In 26-Sep 2 3900 84 Stringer Glass-In 26-Sep 4 4500 100 Stringer Glass-In 26-Sep 5 5400 120 Stringer Glass-In 26-Sep 27 3200 58

Area (closed molding) 27-Sep 68 430 84 Area (hulls) 27-Sep 70 680 14 Area (hulls) 27-Sep 71 640 10


BLANK 27-Sep 37 0 NA BLANK 27-Sep 38 0 NA BLANK 27-Sep 39 0 NA BLANK 27-Sep 40 0 NA


Gelcoater 27-Sep 41 1400 25 Gelcoaterer 27-Sep 34 1100 37 Gelcoaterer 27-Sep 35 240 56 Gelcoaterer 27-Sep 36 470 11

Hull Laminator 27-Sep 42 2300 53 Hull Laminator 27-Sep 43 1900 41 Hull Laminator 27-Sep 44 1800 41 Hull Laminator 27-Sep 45 2000 46 Hull Laminator 27-Sep 48 1400 34 Hull Laminator 27-Sep 49 680 15 Hull Laminator 27-Sep 50 1400 32

LinerDeck Laminator 27-Sep 53 520 11 LinerDeck Laminator 27-Sep 54 1600 303 LinerDeck Laminator 27-Sep 55 2500 502 LinerDeck Laminator 27-Sep 56 1800 338 LinerDeck Laminator 27-Sep 57 1300 242

16

LinerDeck Laminator 27-Sep 58 1900 365 LinerDeck Laminator 27-Sep 59 4300 82 LinerDeck Laminator 27-Sep 63 200 35 Small Parts Laminator 27-Sep 51 1600 35 Small Parts Laminator 27-Sep 62 2100 37 Small Parts Laminator 27-Sep 64 2200 37



Area (Liners Decks) 28-Sep 105 1100 21 Area (Liners Decks) 28-Sep 106 520 96 Area (small parts) 28-Sep 103 410 84



Gelcoater 28-Sep 78 1500 43 Gelcoater 28-Sep 79 1100 18 Gelcoater 28-Sep 80 1500 25 Gelcoater 28-Sep 81 1500 25


LinerDeck Laminator 28-Sep 88 960 27 LinerDeck Laminator 28-Sep 89 2400 52 LinerDeck Laminator 28-Sep 90 1700 41 LinerDeck Laminator 28-Sep 93 3400 79 LinerDeck Laminator 28-Sep 95 750 14 LinerDeck Laminator 28-Sep 96 1100 20 LinerDeck Laminator 28-Sep 98 280 5 LinerDeck Laminator 28-Sep 99 210 40 Small Parts Laminator 28-Sep 109 2600 44 Small Parts Laminator 28-Sep 110 2000 34


17

SITE SURVEYED Grady-White Greenville North Carolina

NAICS CODE 336612 (Boat Building)

SURVEY DATE September 26-28 2007

SURVEY CONDUCTED BY Leo M Blade CIH NIOSH Cincinnati OH

Alberto Garcia MS NIOSH Cincinnati OH

Duane Hammond PE NIOSH Cincinnati OH

EMPLOYER REPRESENTATIVES Jim Hardin CONTACTED Compliance Manager Grady-White

ii

DISCLAIMER



iii

ACKNOWLEDGEMENT


iv

ABSTRACT


1

INTRODUCTION







2






3





4





C

Bay 1

Airflow

Bay 3Bay 2

A

B

Storage


Molds


5

Supply air

Exhaust Plenum

Work Area


Exhaust






6





METHODS


7





mC (1)

V 426



8






9












10

DISCUSSION





11







12

REFERENCES












13












14














15











16











17

DISCLAIMER



iii

ACKNOWLEDGEMENT


iv

ABSTRACT


1

INTRODUCTION







2






3





4





C

Bay 1

Airflow

Bay 3Bay 2

A

B

Storage


Molds


5

Supply air

Exhaust Plenum

Work Area


Exhaust






6





METHODS


7





mC (1)

V 426



8






9












10

DISCUSSION





11







12

REFERENCES












13












14














15











16











17

ACKNOWLEDGEMENT


iv

ABSTRACT


1

INTRODUCTION







2






3





4





C

Bay 1

Airflow

Bay 3Bay 2

A

B

Storage


Molds


5

Supply air

Exhaust Plenum

Work Area


Exhaust






6





METHODS


7





mC (1)

V 426



8






9












10

DISCUSSION





11







12

REFERENCES












13












14














15











16











17

ABSTRACT


1

INTRODUCTION







2






3





4





C

Bay 1

Airflow

Bay 3Bay 2

A

B

Storage


Molds


5

Supply air

Exhaust Plenum

Work Area


Exhaust






6





METHODS


7





mC (1)

V 426



8






9












10

DISCUSSION





11







12

REFERENCES












13












14














15











16











17

INTRODUCTION







2






3





4





C

Bay 1

Airflow

Bay 3Bay 2

A

B

Storage


Molds


5

Supply air

Exhaust Plenum

Work Area


Exhaust






6





METHODS


7





mC (1)

V 426



8






9












10

DISCUSSION





11







12

REFERENCES












13












14














15











16











17






3





4





C

Bay 1

Airflow

Bay 3Bay 2

A

B

Storage


Molds


5

Supply air

Exhaust Plenum

Work Area


Exhaust






6





METHODS


7





mC (1)

V 426



8






9












10

DISCUSSION





11







12

REFERENCES












13












14














15











16











17





4





C

Bay 1

Airflow

Bay 3Bay 2

A

B

Storage


Molds


5

Supply air

Exhaust Plenum

Work Area


Exhaust






6





METHODS


7





mC (1)

V 426



8






9












10

DISCUSSION





11







12

REFERENCES












13












14














15











16











17





C

Bay 1

Airflow

Bay 3Bay 2

A

B

Storage


Molds


5

Supply air

Exhaust Plenum

Work Area


Exhaust






6





METHODS


7





mC (1)

V 426



8






9












10

DISCUSSION





11







12

REFERENCES












13












14














15











16











17

Supply air

Exhaust Plenum

Work Area


Exhaust






6





METHODS


7





mC (1)

V 426



8






9












10

DISCUSSION





11







12

REFERENCES












13












14














15











16











17





METHODS


7





mC (1)

V 426



8






9












10

DISCUSSION





11







12

REFERENCES












13












14














15











16











17





mC (1)

V 426



8






9












10

DISCUSSION





11







12

REFERENCES












13












14














15











16











17






9












10

DISCUSSION





11







12

REFERENCES












13












14














15











16











17












10

DISCUSSION





11







12

REFERENCES












13












14














15











16











17

DISCUSSION





11







12

REFERENCES












13












14














15











16











17







12

REFERENCES












13












14














15











16











17

REFERENCES












13












14














15











16











17












14














15











16











17














15











16











17











16











17











17

in-depth survey report: styrene and noise … · naics code: 336612 (boat building) survey date:...

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